Dynamic uptake of drug norfloxacin from aqueous solution using spent tea leaves as a sorbent

Abstract

This work describes sorptive removal of antibiotic drug norfloxacin using spent tea leaves (STL) as a cost effective sorbent. The specific surface area (BET) of spent tea leaves was 1.141 m2gm–1. The effect of pH, initial concentration of drug, contact time and particle size on the extent of adsorption were studied. The kinetic uptake data were best interpreted by pseudo second order kinetic model. The values of rate constants of adsorption were found to be 29.34 × 10–4 and 8.28 × 10–4 g mg–1 min–1 respectively for the initial sorbate concentrations of 60 and 100 mg L–1 at 27°C. The sorption mean free energy was determined from the Dubinin Radushkevich (DR) equation and was found to be 7.936 kJ mol–1, indicating physical nature of uptake process. The drug uptake was found to increase with pH of sorbate solution and maximum sorption was observed in the pH range of 6.5 to 7.3 at 27°C.